铽(III)掺杂TiO2纳米材料相转移和光催化性质研究

以无水丁二醇为溶剂在中性条件下用溶胶凝胶法制备了系列Tb~(3+)(x=0. 0025～0.07)均匀掺杂的二氧化钛纳米材料。研究结果表明，Tb~(3+)掺杂对纳米二 氧化钛的相转移有很强的抑制作用。这种抑制作用的强弱与Tb~(3+)掺杂的浓度有 密切关系，Tb~(3+)(x = 0.02)的掺杂对TiO_2锐钛矿(anatase)向金红石(rutile) 转化的抑制作用最强。伴随着发生相转移温度的提高，掺杂纳米二氧化钛材料的高 温烧结大大缓解，掺杂纳米TiO_2的热稳定性明显增强；掺杂浓度越高，热稳定性 提高越大。对罗丹明的光降解实验表明，Tb~(3+)掺杂可以有效提高TiO_2光催化活 性。对不同浓度、不同煅烧温度样品光催化降解活性进行系统考察后发现，Tb~ (3+)(x=0.02)掺杂的样品在不同煅烧温度下均显示出最好的光催化效率，说明掺杂 浓度对其光催化性质影响很大。用浸渍法制备的样品其光催化活性较纯的二氧化钛 低，并且其催化活性随浸渍浓度的增加而降低，表明稀土离子的分布是影响稀土掺 杂纳米TiO_2光催化性质的主要因素之一。

Phase Transition and Photocatalytic Properties of Terbium Doped Nanosized Titanium Dioxide

The preparations of a series of terbium doped nanocrystalline TiO 2 materials are described. The materials have been characterized by XRD and TEM. It shows that Tb 3+ dopant not only significantly inhibits the phase transition of nanocrystalline TiO 2, but also remarkably increases its thermal stability. The investigation of degradation of rhodamin B under irradiation of UV light demonstrates that the photocatalytic activity of nanocrystalline TiO 2 is greatly improved by Tb 3+ dopant with Tb 3+ ( x =0.02) doped samples exhibiting the best activity.